Table 1.

Brief description of the Strongyloides stages in dogs and cats

Characteristics	S. stercoralis	S. felis	S. tumefaciens	S. planiceps
Location of parasitic female in host	Small intestine	Small intestine	Colonic nodules	Small intestine
Length of parasitic female (mm)	2–3	2.3–3.6	5a	2.4–3.3
Ovaries of parasitic female	Straight	Straight	Straight	Spiraled
Tail of parasitic female	Bluntly pointed	Bluntly pointed	Bluntly pointed	Bluntly rounded
Stage found in feces	Rhabditiform (L1) larvae	Rhabditiform (L1) larvae	Not indicated	Larvated eggs
Egg size (µm)	42–58 × 30–34	Similar to S. stercoralis	114–124 × 62–68	32–40 × 58–64
Length of L1 (µm)	180–380	217–238	200	270–520
Length of L3 (µm)	568–662	525–615	Not indicated	490–670
References	[20, 54, 55]	[14, 15]	[24]	[17]

^aThe length was estimated from pieces of two different worms dissected out from formalin embedded tissue

Abbreviations: L1, first-stage, rhabditiform larvae; L3, third-stage, filariform larvae